Ductless air conditioning: Things to consider

Similar to a central air-conditioning unit, a ductless system has a split design, but it doesn't use the duct work in your home. An evaporator is installed in the home, and the condenser is placed outside the home. Tubes filled with refrigerant run from the outside unit to the inside unit. A unit can cool a single room, and up to four units can be used with a single condenser.


A single-zone system has one condenser and one evaporator and is used to cool one room or area. For large areas or multiple rooms, you will need a multiple-zone split system. This allows you to use up to four indoor units from only one condenser.

In a multiple-zone system, each unit can be set to a different temperature and each unit runs independently. If you want to cool your entire home with this type of cooling, it's best to have a unit for each room. Unlike with central A/C, you can set the temperature at different settings for each room to save energy.


Installing a ductless system is not as complicated as a central A/C system, but it's more involved than installing a window or wall unit. An HVAC professional will need to run lines for coolant, electricity, and drainage. The unit must also be charged with the correct amount of refrigerant.

Additional materials

You will need to purchase line sets, also called tubing, to install the ductless system. These lines connect the indoor and outdoor units. You will also need a condensate pump to remove condensation from the outside unit if you are installing the system on an interior wall.


Some ductless systems also provide heat. You may need to purchase a separate heat pump, but some models come with heat strips already installed.


  • Ductless cooling is more expensive than a window unit, but cheaper than central A/C.
  • They're quieter than wall or window units because the compressor is outside.
  • You don't need to vent from the inside, so you can install the unit in a room without an exterior wall.


  • It requires professional installation.
  • You need to cut a 3-inch hole in the wall for pipes and tubing.

For more information, visit the Angie's List Guide to Heating and Cooling.

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I do not think your statement about ductless costs is quite accurate. "...Ductless cooling is more expensive than a window unit, but cheaper than central A/C." I agree with the first part - ducltess is definitely more expensive than a window unit but I have found that ductless is also more expensive than ducted AC for a whole house solution. Perhaps you are refering to ductless being less expensive than running new ductwork to a small, one room add on space or something - I would agree with that. Ductless solutions are ideal for room expansions, or garage/attic renovations. A whole house ductless solution is pretty expensive and might have other problems too - especially in lager homes. Would you agree with this clarification? Thanks!

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